Blender rendering makes my pc randomly die and restart
Sorry didn't quite understand, did you mention you made a pc upgrade to your motherboard RAM and graphics card? Did the cashes start happening only after the upgrade?

If it's crashing your whole computer it is likely a hardware problem, and not Blender related, though it is hard to say.

Rendering is a pretty demanding task that taxes your computer hardware, it may be overheating, or your power source may be insufficient for all your hardware and that is only revealed on heavy tasks,hard to tell this way.

Have you tried using some sort of hardware or system monitor with logging capabilities while rendering? Maybe it provides some insight into what is happening.